diff --git a/PyReconstruct/modules/gui/utils/errors.py b/PyReconstruct/modules/gui/utils/errors.py
index ae9c558f..694edf0d 100644
--- a/PyReconstruct/modules/gui/utils/errors.py
+++ b/PyReconstruct/modules/gui/utils/errors.py
@@ -1,27 +1,120 @@
 import sys
+import html
+import platform
+import traceback as _traceback
 
-from PySide6.QtWidgets import QApplication, QMessageBox
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QFontDatabase
+from PySide6.QtWidgets import (
+    QApplication,
+    QMessageBox,
+    QDialog,
+    QVBoxLayout,
+    QHBoxLayout,
+    QLabel,
+    QPlainTextEdit,
+    QPushButton,
+)
 
 from PyReconstruct.modules.constants import gh_issues
 
 
-def customExcepthook(exctype, value, traceback):
-    """Global exception hook: Show notification."""
-    sys.__excepthook__(exctype, value, traceback)  # call default exception hook
-            
-    message = (
-        f"An error occurred:\n\n{str(value)}\n\n"
-        "(See console for more info.)\n\n"
-        "If you think this is a bug or need help, "
-        "please issue a bug report at:\n\n"
-        f"{gh_issues}"
+def build_error_report(exctype, value, tb) -> str:
+    """Assemble a paste-ready crash report: version / OS / Python context plus the
+    full traceback. Never raises -- the global exception hook must not itself fail.
+    """
+    lines = ["PyReconstruct error report"]
+    try:
+        from PyReconstruct.modules.backend.updater.install_info import current_version_str
+        lines.append(f"Version:  {current_version_str()}")
+    except Exception:
+        pass
+    try:
+        lines.append(f"Platform: {platform.platform()}")
+        lines.append(f"Python:   {platform.python_version()}")
+    except Exception:
+        pass
+    lines.append("")
+    try:
+        tb_text = "".join(_traceback.format_exception(exctype, value, tb)).rstrip()
+    except Exception:
+        tb_text = f"{getattr(exctype, '__name__', exctype)}: {value}"
+    lines.append(tb_text or "(no traceback available)")
+    return "\n".join(lines)
+
+
+class ErrorReportDialog(QDialog):
+    """Modal error window that shows a copyable report.
+
+    The frozen app has no console, so lay users cannot read the traceback that
+    ``sys.__excepthook__`` prints to stderr. This shows the full report inline and
+    a one-click "Copy report to clipboard" button so it can be pasted into a bug
+    report or email.
+    """
+
+    def __init__(self, summary_html: str, report: str, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("Error")
+        self._report = report
+
+        layout = QVBoxLayout(self)
+
+        heading = QLabel(summary_html)
+        heading.setWordWrap(True)
+        heading.setTextFormat(Qt.RichText)
+        heading.setTextInteractionFlags(Qt.TextBrowserInteraction)
+        heading.setOpenExternalLinks(True)
+        layout.addWidget(heading)
+
+        view = QPlainTextEdit(report)
+        view.setReadOnly(True)
+        view.setLineWrapMode(QPlainTextEdit.NoWrap)
+        view.setFont(QFontDatabase.systemFont(QFontDatabase.FixedFont))
+        layout.addWidget(view)
+
+        buttons = QHBoxLayout()
+        self._copy_btn = QPushButton("Copy report to clipboard")
+        self._copy_btn.clicked.connect(self._copyReport)
+        close_btn = QPushButton("Close")
+        close_btn.clicked.connect(self.accept)
+        close_btn.setDefault(True)
+        buttons.addWidget(self._copy_btn)
+        buttons.addStretch()
+        buttons.addWidget(close_btn)
+        layout.addLayout(buttons)
+
+        self.resize(720, 480)
+
+    def _copyReport(self):
+        clipboard = QApplication.clipboard()
+        if clipboard is not None:
+            clipboard.setText(self._report)
+        self._copy_btn.setText("Copied ✓")
+
+
+def customExcepthook(exctype, value, tb):
+    """Global exception hook: show an error window with a copyable report."""
+    sys.__excepthook__(exctype, value, tb)  # keep console output for terminal users
+
+    report = build_error_report(exctype, value, tb)
+
+    summary = (
+        f"<b>An error occurred:</b><br><br>{html.escape(str(value))}<br><br>"
+        "Click <b>Copy report to clipboard</b> below, then paste it into a bug "
+        "report or email so we can help.<br><br>"
+        f'Report bugs at <a href="{gh_issues}">{gh_issues}</a>'
     )
 
     active_window = QApplication.activeWindow()
     parent = active_window if active_window else None
-    
-    QMessageBox.critical(parent, "Error", message, QMessageBox.Ok)
-    
+
+    try:
+        ErrorReportDialog(summary, report, parent).exec()
+    except Exception:
+        # the error handler itself must never fail -- fall back to a plain box
+        QMessageBox.critical(
+            parent, "Error", f"{str(value)}\n\n{gh_issues}", QMessageBox.Ok
+        )
+
     if active_window:
         active_window.activateWindow()
-        
diff --git a/tests/test_error_report.py b/tests/test_error_report.py
new file mode 100644
index 00000000..72fd0852
--- /dev/null
+++ b/tests/test_error_report.py
@@ -0,0 +1,27 @@
+"""The crash-report builder behind the copyable error dialog.
+
+The frozen app has no console, so the report (shown + copied to clipboard) must
+carry the full traceback + context, and the builder must never itself raise
+(it runs inside the global exception hook).
+"""
+import sys
+
+from PyReconstruct.modules.gui.utils.errors import build_error_report
+
+
+def test_report_has_traceback_and_context():
+    try:
+        raise ValueError("boom-marker-123")
+    except ValueError:
+        exctype, value, tb = sys.exc_info()
+    report = build_error_report(exctype, value, tb)
+    assert "boom-marker-123" in report     # the exception message
+    assert "ValueError" in report          # the exception type
+    assert "Traceback" in report           # the stack
+    assert "Platform:" in report and "Python:" in report   # context
+
+
+def test_report_never_raises_on_bad_input():
+    # the exception hook must not fail even on degenerate inputs
+    assert isinstance(build_error_report(None, None, None), str)
+    assert isinstance(build_error_report(ValueError, ValueError("x"), None), str)